Cluster B Personality Disorder Is Independently Associated With Opioid Abuse at Two and Five Years After Primary Total Knee Arthroplasty.

BACKGROUND

Psychiatric comorbidities are associated with worse results after total knee arthroplasty (TKA), but outcomes in patients who have personality disorders (PD) remain poorly defined. This study evaluated complications and opioid-related outcomes after primary TKA in patients who have PD.

METHODS

Patients who underwent primary TKA from 2010 to 2022 were identified in a national all-payer claims database. Patients who had PD were identified by diagnosis codes and classified by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition cluster. Because they carried a greater baseline comorbidity burden, patients who had PD were matched 1:1 to patients who did not have PD on demographics, comorbidities, psychiatric conditions, and preoperative opioid abuse. Multivariable regressions evaluated medical, wound and infectious, orthopaedic, and opioid-related outcomes.

RESULTS

Of 698,040 patients, 2,961 (0.4%) had PD; 75.7% had Cluster B PD, of which 81.1% were borderline. After matching (n = 2,922 per group) and adjustment, PD was independently associated with opioid abuse at two years (odds ratio [OR] 1.26; 95% confidence interval [CI], 1.04 to 1.52) and five years (OR 1.36; CI, 1.15 to 1.60), and with lower odds of wound and infectious complications (OR 0.80; CI, 0.67 to 0.95); all P < 0.05. Total 90-day opioid exposure in morphine milligram equivalents did not differ. Only Cluster B PD remained associated with opioid abuse at two years (OR 1.39; CI, 1.19 to 1.63) and five years (OR 1.43; CI, 1.25 to 1.64; both P < 0.001).

CONCLUSIONS

The greater baseline comorbidity burden of patients who have PD accounts for most of the excess perioperative risk. However, Cluster B PD remains independently associated with opioid abuse at two and five years after TKA despite similar opioid exposure, supporting preoperative psychiatric screening and targeted opioid stewardship.